Icom IC-7100 PTT Issues

When I bought a Digirig, my plan was to use it with my Icom IC-7100 and Direwolf for APRS activities. I also bought the MiniDin6 Audio cable to use with the 7100’s DATA1 jack.

However I was not able to get the 7100 to recognize PTT from the Digirig. Using the troubleshooting information on the Digirig website, I was able to determine the Digirig was in fact activating PTT thru its audio jack as expected. But the radio wasn’t going into transmit.

I soon learned the uart in the IC-7100 receives RTS as a result of an external PTT thru the Data1 jack (MiniDin6) but isn’t designed to do anything with it.

The past couple of years I had been using a Signalink with my 7100 for APRS. In that case I had the Signalink connected to the 7100’s control head with a RJ45 cable, so I knew the 7100 recognized PTT thru the control head. At the time I did have to build a special RJ45 cable. I also had to build a separate speaker cable since the 7100 doesn’t provide the speaker thru the RJ45 jack.

With that in mind I rechecked the Digirig store to see if such an IC-7100 cable was available for the Digirig. I did find the " ICOM RJ-45 Cable for Digirig Mobile", but it didn’t list the IC-7100.

So I went to work and built one to match my IC-7100 based on its schematics. As it turned out, I believe the Digirig one would have worked just fine for the 7100. Someone might want to confirm that before adding the IC-7100 to the list.

Anyway, at this point I’m successfully using my Digirig with my IC-7100 with Direwolf for APRS, JTDX, VarAC, JS8CALL, Fldigi. Just to be clear, I’m not using the MiniDin6 cable or Data1 port at all.

Thanks for the info. The recommended cable kit for IC-7100 is the one with 13 pin accessory connector:

Looking at the manual for IC-7100 it states PTT support in MiniDin6:

This may be limited to FM or UHF/VHF since the manual mentions “packet”. Try simulating the PTT by shorting the sleeve to ring 2 on the other end of the MiniDin6 cable with the radio on different bands to see if this is the case.

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I just tried shorting PTT to GND on the MiniDin6 cable, and your suspicion is correct. It only activates PTT in VHF/UHF. You said the recommended cable is the the one for the 13 pin ACC jack, but do you know if it also only works on VHF/UHF?

Apparently PTT in the control head must bypass the 13-pin ACC and 6-pin DATA jacks? I have the 7100’s service manual & schematics, but block diagrams don’t help explain firmware details like this.

13 pin connector has multiple PTT lines for different bands. Digirig cable activates them all.
You can confirm the functions by shorting the PTT lines on the connector directly.

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Very good - I’m going to order one. I could build it, but I like your cables with the built-in ferrite beads. My RJ45 setup works, but it’s kind of clunky looking.

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